524 Chemical and Materials Engineering Building
(780) 492-3962
Fax: (780) 492-2881
mike.williams@ualberta.ca

Research Areas: Composite Materials, Fluid Mechanics, Mechanical Properties, Polymers, Rheology 

DR WILLIAMS' academic research over the past 29 years (24.5 yrs at the University of California, Berkeley) has been directed primarily toward the general fields of rheology and polymers and has led to over 150 research publications. Primary focus has been on polymer rheology--non-Newtonian and viscoelastic liquid models (continuum and molecular) and property measurements on solutions, melts, and gels. Fluid mechanics problems relevant to polymer melt processing have also been addressed. Other important fluids studied rheologically have been blood, coal suspensions, and fluidized beds. A major effort has involved block copolymers, initially directed toward the thermodynamics of their microphase separation transitions and microstructure development and then moving on toward their rheology. Additional research has involved biomaterials (polymers) in connection with blood compatibility, the use of polymer additives in airplane fuel to promote fire safety, the deposition of aerosol coatings on crop leaves to retard transpiration water loss, modelling the flow of sickle erythrocytes in capillaries, the chemistry (including polymerization) of hydrocarbon gas plasmas in wire chambers, and the properties of multiphase polymer blends. Two new research ventures have emerged here in the past 2-3 years. One is centered in the area of polymer composites, with focus being specifically on long-fibre reinforcement (glass, or carbon) and improvements in fibre/polymer bonding. The second new area is directed at polyethylene (PE) and the properties that arise when different forms of PE are blended together. 

Currently our laboratory is equipped with a state-of-the-art rheological instrument (Rheometrics Mechanical Spectrometer 800) for comprehensive measurements on liquids. This is used for a broad spectrum of rheological measurements. A Brabender Prep Centre is in place, equipped with a 3/4 inch extruder and a mixing head for liquid-state blending. A wide range of thermal properties (glass transition and crystallization behaviour; phase separation of block copolymers and polymer blends) can be studied with our top-of-the-line differential scanning calorimeter. Electron microscopy of several types is also being used to characterize multiphase polymer systems. Among specific projects are: 

1. Thermorheology of Block Copolymers, wherein the flow process itself is investigated as a thermodynamic factor (through strain energy, perhaps) which can influence microphase separation and the nature of microstructures. 
2. Microphase Separation in Block Copolymer Blends, which explores the compatibility of diblock and triblock copolymers with homopolymers that match one block of the other and investigates the morphologies which form upon phase separation. 
3. Rheology of Block Copolymer Blends, which seeks to explain the novel viscous and elastic properties of these materials in the liquid and solid states and uses those properties to monitor the kinetics of microstructure development over a range of temperatures. 
4. Phase Separation and Rheology of Polyethylene Blends, which explores the new recognition that different forms of PE may not be compatible with each other. 
5. Long-Fibre Composites from Ring-Opening Thermoplastics, developing superior mechanical properties and new schemes for molding products from these novel high-tech materials. 

• Wardhaugh, L.T. and Williams, M.C., 1995, "Blockiness of Olefin Copolymers and Possible Microphase Separation in the Melt", Polymer Eng Sci, 35, 18-27.
• Spaans, R.D. and Williams, M.C., 1995, "Nonlinear Viscoelasticity of ABA Block Copolymer Melts: Stress Relaxation and Recovery", Indus Eng Chem Res, 34, 3496-3507.
• Hussein, I.A. and Williams, M.C., 1998, "Rheological Evidence for High-Temperature Phase Transitions in Melts of High-Density Polyethylene", Macromolecular Rapid Communications, 19, 323-325.
• Hussein, I.A. and Williams, M.C., 1999, "Anomalous Nonlinearities in Steady Shear of Polyethylene Melts", J Non-Newtonian Fluid Mechanics, in press.
• Spaans, R.D., Muhammad, M. and Williams, M.C., 1999, "Interfacial Region of Microphase-Separated Block Copolymers by Differential Scanning Calorimetry", J Polym Sci, Polym Phys Ed, 37, 267-274.